Plasma fibrinogen as a predictor of blood component transfusion in the perioperative period in patients undergoing major orthopaedic surgery: a cohort study.

Background: There is a trend towards increased perioperative bleeding in patients with plasma fibrinogen levels < 200 mg.dL-1. This study aimed to assess whether there is an association between preoperative fibrinogen levels and blood components transfusion up to 48 hours after major orthopaedic surgery. Matherials and methods: This observational cohort study included 195 adult patients of both sexes who underwent primary hip arthroplasty or revision hip arthroplasty for non-traumatic aetiologies. Plasma fibrinogen, blood count, coagulogram, and platelet count were measured in the preoperative period. A plasma fibrinogen level of 200 mg.dL-1 was the cut-off value used to predict blood components transfusion. Results: The mean (SD) plasma fibrinogen value was 325 (83) mg.dL-1; only 13 patients had values < 200 mg.dL-1, and only one of these received a blood transfusion, with an absolute risk of 7.69% (1/13; 95% CI: 1.37% - 33.31%). There was no association between preoperative plasma fibrinogen values and blood transfusion (p = 0.745). The sensitivity and the positive predictive value of plasma fibrinogen < 200 mg.dL-1 as a predictor of blood transfusion were 4.17% (95% CI: 0.11% - 21.12%) and 7.69% (95% CI: 1.12% - 37.99%), respectively. The accuracy of the test was 82.05% (95% CI: 75.93% - 87.17%), but both positive and negative likelihood ratios were poor. Conclusion: Preoperative plasma fibrinogen level in hip arthroplasty patients was not associated with blood components transfusion and is ineffective as a biomarker for blood components transfusion risk.